In general, secondary batteries refer to chargeable and dischargeable, unlike primary batteries that are not chargeable. The secondary batteries are being widely used in the high-tech electronic fields such as mobile phones, notebook computers, and camcorders.
Such a secondary battery is provided with one or more battery cells. Each of the battery cells comprises an electrode assembly and a case in which an electrolyte is accommodated together with the electrode assembly.
That is, the battery cell is manufactured by injecting the electrolyte into the case in which the electrode assembly is accommodated after the electrode assembly is accommodated into the case. Here, the electrolyte is impregnated into the electrode assembly while being absorbed into the electrode assembly.
However, the battery cell has a problem in which the electrolyte injected into the case is not absorbed up to the inside of the electrode assembly.